Checking the performance of a balance and calculating its minimum weight is an important factor in ensuring accurate weighing in today’s regulated laboratories.
In a recent webinar, now available on demand, A&D Instruments’ European Director of Weighing, Steve Vaughan, outlines a patented new technology from A&D called Electronically Controlled Load™ (ECL) — incorporated in the companies APOLLO series GF-A/GX-A balances — which allows automatic precision assessment of a balance and determination of minimum weight, at the simple touch of a button.
The webinar covers:
Missed the live event? Don’t worry, you can watch the webinar on-demand>>
At the end of the webinar, our guest speaker answered live questions from attendees, the highlights of this Q&A session can be read below.
Why not report exact weight for ECL?
Because ECL isn't actually a weight. It's electronically controlled load – we're not actually weighing anything. What we're doing is simulating a weight by applying a current to the magnets, so the net result is around a 6-gram effective weight.
How do you calibrate ECL on the APOLLO series balances?
Calibration is exactly the same with any other balance, really. The GF-A version has an internal calibration weight, so basically you can press a button to calibrate it, or it will, in fact, calibrate itself when it sees a temperature change in the lab of more than a couple of degrees. The GF version doesn't use internal calibration weight, and it's a bit cheaper for that reason. The GF requires an external weight. In both cases, we would recommend you regularly check the calibration with an external weight, just to make sure everything is all properly correct with the internal weight.
Should I check the ECL function against real weight?
Yes, absolutely. We're putting ECL out there as a new technology, so it's important you check it occasionally, just to make sure nothing has gone astray or strange in the technology. I didn't cover this in the presentation, but you can also choose to manually input a minimum weight – so if you've determined it by actual weight, you can input the minimum weights at that stage and override the ECL function.
Can I use this in place of weights in my balance performance qualification (PQ) to determine minimum weight?
We believe this technology will help you in the PQ or an SOP situation. We're not saying it should replace your minimum weights, but using weights, you could work in hand with it. I think it would be something you could use routinely and then check externally, but it will be down to each individual customer to determine how often they would want to check the ECL function.
What is USP's feedback on the ECL approach?
This is new technology that we've just recently launched, so we're very keen to work with USP. We do have a letter – which I can share with anybody on the call that would like to get a copy of that – but we're also really keen to work with some opinion leaders on this. We would be keen to partner with any experts in this subject matter area to produce some validated scientific data that we could publish jointly. We're not, at this stage, saying the ECL approach is a replacement – this is some additional assistance for you if you are working in that regulated environment.
How do you check repeatability of the balance?
Repeatability is something that you can easily check. If you've got an external weight, you will be able to do that just by doing a series of repetitive weights.
Factors that we have considered as a manufacturer include load error – so if you weigh the weight of the extreme edges of the pan, do you get differences in weight? When a balance has been in situ for a number of years, or possibly used less than delicately, that's one of the things that could go out, particularly for balances regularly serviced. To help avoid this, the APOLLO balances incorporate a feature called impact shock detection, which warns the user when they are in danger of damaging the balance.
What are the minimum recommended intervals of performing the repeatability checks where handling of weights is quite difficult?
We would suggest that you check repeatability at the start of a shift, or the start of a day's work, or, if you're running in a 24-hour environment at handover, or if something in the lab has changed, such as temperature or air flow. We can understand that's quite a long process, which is why we've presented ECL technology as a quick way of determining whether anything has fundamentally changed. I think, over time, the customer will get to see whether they're getting significant variability of the standard deviation using ECL or not.
Find out more about the APOLLO series GF-A/GX-A balances
What are some of the other features of the APOLLO balances?
The ECL is obviously what the Apollo series is best known for. However, I also mentioned the impact shock detection feature, which is a visual and audio warning on the display where the balance is telling you that you're using it a little bit roughly.
In many places around the world, our balances are used in industrial applications as well as lab, and some of those applications could be a little bit rugged. The worst thing you can do to a balance is to shock the weighing mechanism, not overload the balances. A lot of balances have overload protection built in, but shocking it by hitting it with a sudden weight is the worst thing you can do. Impact shock detection is a way of warning you that you are in danger of damaging the balance. The more you shock it, the more visible the warning on the display and the louder the beeping is.
Another key feature on the Apollo is what we call a flow rate display, and that is a way that the balance can be used in synchronization with a peristaltic pump to accurately measure and control the accurate dispensing of a liquid to a very tight tolerance, which is quite a specialist application of anybody dispensing and controlling very small amounts or very great size amounts of a flow.
Otherwise, we're very much a company that focuses on core performance rather than on flashing lights and bells, so what we've built in the APOLLO is a very rugged, reliable, repeatable balance, but also good value for money with specific features that we think are really useful.
Download: Verification of a Method for Testing Repeatability of Electronic Balances Without Using a Weight
Download: ECL and the USP Minimum Weight Standard
Download: Automatically Calculate Flow Rate Based on Change of Mass Over Time
You can catch up with the on-demand version of this webinar at a time that suits you
SelectScience runs 3-4 webinars a month across various scientific topics, discover more of our upcoming webinars>>